The present invention relates to carding segments of carding machines, particularly flat carding machines, in which carding segments are arranged against the circumference of a rotary drum provide with card clothing, which carding segments are stationary or longitudinally movable and provided with unevenly arranged tips cooperating with the card clothing of the drum.
It has been known in the art that wire card clothings of various depth, various stability and various height have been utilized on the lids of the lid chain of the carding machine. Such card clothings have been disclosed, for example in U.S. Pat. No. 3,151,362 or Japanese Pat. No. 54-40661.
It has also been known that individual lids can be covered with carding plates instead of card clothing. Many reasons could be found for such arrangements. These arrangements are satisfactory for improved refuse removal, deeper carding and for simple cleaning.
Known card clothing have been also described in German patent publications DE No. 2,617,796 and DE No. 2,226,914. A commonly known card clothing includes a plurality of tips arranged one after another. These tips, in spite of staggering difference in distance between individual tips, operate simultaneously. Such operation causes high carding forces, particularly in the inflow region, or on the carding segments positioned between the licker-in and the lid chain or on the lids of the lid chain. Extensive wear of the card clothing obviously results from such an arrangement. To avoid this disadvantage it has been suggested, as described in DE No. 52,874, to utilize rigid overall-steel card clothing in place of elastic card clothing. However, complicated processes and rare and expensive materials have been required to obtain the necessary hardness and wear properties of the rigid card clothing, as is disclosed in U.S. Pat. No. 3,833,968.
In order to substantially equalize carding forces, particularly those acting on the stationary carding segments, positioned between the licker-in and the lid chain, the tips of the card clothing are arranged at a different distance from each other so that the distance between the tips is decreased in the direction of carding. This resulted in increased carding output and a longer life span of the card clothing.
As has been mentioned above, conventional card clothings are expensive and it has been difficult to produce card clothings with a uniform hardness and good wear resistance. Furthermore, the life span of known card clothings has been substantially limited.